The Scotland and Lions pair left Edinburgh for Sixways last summer and although the West Midlands club have been struggling at the wrong end of the Gallagher Premiership they have the chance to finish the campaign with a flourish.
Van der Merwe has been picked on the left wing for the match at the Brentford Community Stadium while Sutherland starts on the bench for Worcester.
There is a tartan flavour to the London Irish side, with Scotland scrum-half Ben White starting. Also playing for the Exiles is teenage sensation Henry Arundell, the full-back who notched a stunning try for England against Scotland in the Under-20 Six Nations in Edinburgh in February.
Arundell, who ran the length of the pitch to score at the DAM Health Stadium, is also eligible for Scotland and Wales but is set to be named in a full England squad for the first time on Tuesday, with head coach Eddie Jones expected to include the prodigiously talented 19-year-old in his selection for a training camp.
Arundell’s stock has risen sharply in recent weeks. He was named man of the match after London Irish’s 42-42 draw with Wasps, despite only playing the last 20 minutes. He then scored another remarkable individual try from almost 100 metres out against Toulon in the European Challenge Cup quarter-finals.